煤制替代燃料多联产系统热力性能对比

煤制替代燃料多联产系统是保证我国能源安全的煤炭清洁高效利用技术之一。通过火用分析方法比较了煤制甲醇、煤制甲烷多联产系统的热力性能,揭示了不同替代燃料多联产系统的火用损失规律和节能机理。结果表明,无调整、适度循环的煤制甲醇、煤制甲烷多联产系统的火用效率分别为53.8%和60.9%。相对于各自的分产系统,甲醇电力多联产系统在化工合成反应、弛放气回收、自备电厂单元的节能潜力和效果更佳,相对节能率可达15.0%;而甲烷电力联产系统在合成气调变和净化单元具有更好的节能潜力,相对节能率为14.2%。均存在最佳循环倍率/最佳化动比,实现化工岛和动力岛不可逆损失之和的最小耦合,使醇电联产系统和甲烷电力联产系统的节能率最高。

Thermodynamic performance comparison of different coal to alternative fuels and power poly-generation systems

Coal to alternative fuels and power poly-generation is one of the clean coal technologies which can enforce energy security. The exergy destruction regularity and energy saving mechanism of different poly-generation systems are revealed by comparing coal to methanol and coal to substitute natural gas (SNG) poly-generation systems using exergy analysis method. Results show that the exergy efficiency of syngas non-adjustment, unreacted syngas partial-cycle coal to methanol and coal to SNG poly-generation systems are 53.8% and 60.9%, respectively. Compared to the single-production systems, coal to methanol poly-generation system can save more energy in chemical synthesis reaction, purge gas recovery and captive power plant units with an energy saving ratio (ESR) of 15.0%. Coal to SNG poly-generation system can save more energy in water-gas-shift reaction and clean-up units with an ESR of 14.2%. There is an optimal recycle rate of unreacted syngas which can minimize the sum of exergy destruction in both Chemical Island and Power Island. Thus the two poly-generation systems can achieve a maximum ESR.